| 摘要 |
The present invention provides a composition and method for modifying a hydratable cementitious composition such as concrete or mortar using at least three different, distinct carboxylate polymers, even when clay is present in the concrete or mortar that would otherwise diminish dosage efficiency of polycarboxylate polymer used as dispersant. The three polycarboxylate polymers, designated as Polymer I, Polymer II, and Polymer II, are derived from monomer Components A, B, and C wherein Component A is an unsaturated carboxylic acid, Component B is a polyoxyalkylene, and Component C is an unsaturated carboxylate ester. The component molar ratio ranges for A:B:C are different as between Polymers I and II; while a distinct component molar ratio A:B+C is identified for Polymer III. When treated with these three different polycarboxylate polymers, the hydratable cementitious composition is surprisingly enhanced in terms of initial workability and slump retention, especially if clay is present. |
| 主权项 |
1. A composition for modifying a hydratable cementitious composition, comprising:
three different carboxylate polymers, identified herein as Polymer I, Polymer II, and Polymer III, each of said polymers being obtained from Components A, B, and C in accordance with the component ratios for Polymers I, II, and III as set forth in detail below, wherein: Component A is an unsaturated carboxylic acid monomer represented by structural formula 1, Component B is a polyoxyalkylene monomer represented by structural formula 2: Component C is an unsaturated carboxylate ester or amide monomer represented by structural formula 3:wherein
R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 each individually represent a hydrogen atom, a C1 to C4 alkyl group, or —COOM group wherein M represents a hydrogen atom or an alkali metal; Y represents —(CH2)p— wherein “p” represents an integer of 0 to 6; Z represents —O—, —COO—, —OCO—, —COHN—, or —NHCO—; -(AO)n represents linear repeating ethylene oxide groups, propylene oxide groups, butylene oxide groups, or a mixture thereof; “n” represents the average number of repeating -(AO) groups and is an integer of from 10 to 250; W represents an oxygen atom or an —NH— group, and R11 represents a C1-C10 alkyl group or a C2-C10 hydroxyalkyl group; wherein, in Polymer I, the Components A, B, and C are present in a molar ratio (A:B:C) in the range of 2:1:0 to 5:1:0; and further wherein, in Polymer II, the Components A, B, and C are present in a molar ratio (A:B:C) in the range of 0.1:1:0 to 2:1:0; and and further wherein, in Polymer III, the molar ratio of Component A to the sum of Components B and C is in the range (A:B+C) of 0.3:1 to 3:1. |
